Portable self-protection alarms have been used for alarming purposes in emergency cases of both crime encounters such as theft and rape attempts and natural calamities such as earthquakes and accidents. Such portable self-protection alarms include help voice generators and alarm buzzers. They typically have a battery and a sound generator, such as a voice generator or a buzzer, which are contained in a compact case so that they can be easily carried around. These alarms are designed to generate a very loud sound, when a lever or the like on the alarm is actuated, to thereby sound the alarm for emergency.
When these self-protection alarms are being used, especially in deserted areas such as the mountains, they are usually required to operate for a prolonged period of time such as an entire day or even longer. However, conventional self-protection alarms cannot practically generate a voice or alarm for such a prolonged period of time because they use batteries for power supply.
In addition, there always exists the problem that the volume of the generated sound decreases as the battery is being consumed with the passage of time. Even if the power consumption is minimized in order to operate the alarm for a longer period of time, the volume of the generated sound will eventually decrease, and therefore the alarm will fail to perform its function.
Therefore, it is desirable to provide a sound signal generating device capable of generating an alarm sound signal or voice signal for a prolonged period of time. The present invention provides a sound signal generating device which meets all the requirements.